


Kamen Rider Decade: Cinder’s Fall

by Diabolikal5ME



Category: Kamen Rider Decade, RWBY
Genre: Alternate Universe - Canon Divergence, F/M
Language: English
Status: In-Progress
Published: 2018-01-31
Updated: 2018-03-30
Packaged: 2019-03-11 22:24:41
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 3,928
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13533777
Author URL: https://archiveofourown.org/users/Diabolikal5ME/pseuds/Diabolikal5ME
Summary: After Tsukasa Kadoya’s end in his world, he is given a second chance by Narutaki.Too bad that he ends up as a spirit to the Fall Maiden Cinder Fall.Now armed with both the DecaDriver and her powers, alongside Tsukasa, could Cinder redeem herself and defeat Salem? Or will her lust for power turn her into a second Destroyer of Worlds?





	1. Second Chances

**Author's Note:**

> New story. This idea popped into my head after rewatching all thirty one episodes of Kamen Rider Decade, and after rewatching all of Volume Four of RWBY. This idea also partially came to mind while writing Cinder for my other story, Mass Effect Rebirth. 
> 
> So, this story takes place pre-Volume 4 Of RWBY, and over thirty years after the events of Decade. Also, canon’s pretty much gonna be smashed into pieces. Volume 4 and 5 still have some events happen...just not all of them. 
> 
> Disclaimer: I don’t own RWBY or Kamenr Rider. They belong to Rooster Teeth/ Monty Oum (RIP) and Toei respectively.
> 
> Criticism is always appreciated.

Tsukasa Kadoya.

Both the Savior and Destroyer Of Worlds. A loving father of 2, and a man who once killed every other family in 10 dimensions. A person who’s both a Kamen Rider and Dark Rider. A lover and caring wife of Natsumi Hikari, but a traitor to the fisherman standing in front of him.

Wait, fisherman? What was he even doing here; he died, for crying out loud! Tsukasa lived a good life, whether it was fighting as Kamen Rider Decade in his youth or helping to guide the new Riders into practicing and learning their abilities (while stopping Kaito from stealing anything…again.)

And now, he’s here, standing across from Narutaki, who still gave him the same devilish grin he always had.

“Decade.” He simply states.

“Narutaki.” Tsukasa casually Replied.”Haven’t seen you in twenty something years old man.”

“Trust me, Decade…I’ve been watching you for longer than that.” He states, that same evil grin on his face. “In fact, I’ve been waiting for this very day.”

“Whatever you want, old man, just do it. I’m already dead.”

Tsukasa waved nonchalantly to prove his point.

“Decade…you’re getting a second chance at life.” Narutaki tells him, making Decade a bit more suspicious.

“What do you mean…second chance at life, Narutaki?” Tsukasa Asked, as something materialized in the former Rider’s hand, said Rider widening his eyes in response.

It was the DecaDriver, with his card pack, which contained every Rider from Ichigo to Build. As well, he also held in his other hand the card for the Machine Decader.

Narutaki proceeded to push him straight into a portal that was behind the former Decade.

“You will earn a second chance to become the Destroyer of Worlds, Decade. Embrace the darkness within your host’s soul…and destroy everything…Decade.” Narutaki tells himself, jumping into a second  
portal.

——————————————————————

_(Salem’s Domain…)_

Cinder Fall.  
  
Current Fall Maiden and Killer. Taking out both Pyrrha Nikos and Ozpin was easy…Although while being humiliated by the silver-eyed she came to know as Ruby Rose…she kinda felt bad now that she had time to think about it.

It was Ozpin’s fault that everything had to happen the way it had. She had to kill Pyrrha to stop Ozpin from using her own powers against the Fall Maiden. That she had to kill poor android Penny Polendina to potentially frame Vale and Atlas for allowing someone to die and buy her forced Master Salem time to plan and manipulate. That she had to take out Ozpin in order to free the rest of his cohorts…or just find out where they are so that Ozpin’s manipulation wouldn’t happen again.

Regret was Cinder’s feeling and she hated it.

Even worse when after being dragged back from Beacon by her cohorts Emerald and Mercury. And then being humiliated for nearly 8 months by Salem’s other cohorts. Despite Salem’s orders, she wanted to burn them to a crisp and wrangle their souls until there was nothing left but ashes. As the months of humiliation went on and on, she felt as if she wanted to be free from Salem’s control. Free from the burden of being restricted in what she could and could not do.

But, as she returned to her temporary abode, that wasn’t possible.

Then again, a belt laying on her bed alongside a pack of cards she didn’t seem to recognize shouldn’t be possible either.

 _“What the…”_ was her thought, not wanting to waste what little voice she had currently, as walked up to the Strange belt, picking it up and inspected it. 19 Unknown symbols of some kind were plastered all around a single transparent circle-like object. There was a compartment to place the cards still laying her bed on the top of the belt, which seemed to slide into the circle. There seemed to be a place to hold the cards on the belt as well.

She tried to burn it using her Maiden powers.

It didn’t burn, and in fact, looked the exact same as before…which made Cinder even more intrigued.

 _“Immune To Maiden powers…interesting.”_ She thought to herself, before a voice interrupted her.

“So we are bounded together. Can’t say I’m happy.” A masculine voice was heard behind Cinder, as she decided to throw a fire ball straight into the direction of the man…only to find a transparent man instead.

The man wore what seemed to be casual clothes. Not for someone in Vale, though. A magenta shirt and black pants was on him, alongside black boots, and a grey jacket to place on top of the shirt. A strange looking camera was slug around his neck, making him clearly a photographer.

Which made the whole situation look more creeper than it should’ve been.

 _“What is this guy…some form of pervert?”_ She asked herself, before that same man turned to her.

“You do know I could somehow read your thoughts, right?” The man asked Cinder, which proceeded to promptly freak her out.

 _“How?”_ She asked.

“I’m a ghost. I don’t know, ask Takeru. Wait…you don’t know who he is, don’t you?” The man asked Cinder, slapping his forehead after realizing no one knew who Kamen Rider Ghost was in this dimension.

“ _...I might as well chalk this up to a consequence of having Maiden powers.”_ She had thought to herself.

“…You want to free yourself from this…Salem, don’t you? You and your two friends.” He had questioned to the Maiden, as she proceeded to turn around, realizing and weighing the possibility of going rogue. Sure, being with Salem was getting her and her cohorts almost nowhere, putting themselves in the line of Fire just for it to end in absolute humiliation. Then again, going out on her own against Salem…would that be a good idea? Perhaps she could gain new power that way, not have to exactly follow some stupid plan made by someone else; she could make her own plans, just like how she did it in Vale.

 _“Why should I trust a Ghost I just met out of all people? What happens if you’re just another of Salem’s figments, trying to test me?”_ The Fall Maiden asked him within her head, her anger clearly being seen somewhat rising.

“I don’t know if can trust me, honestly. But that belt…that belt…it’ll give you a second chance. A chance to become a savior. Or a Destroyer. I can simply guide you and help you; no matter what, we are bonded. If you die, I die. None of us get another chance like this.” The mysterious man warns her, clearly annoyed at the whole idea of being forced with Cinder.

  
After a moment of thinking, she began to speak to the man.

 _“…So you’ll help me use whatever this stupid belt’s purpose is, and in trade…I can do whatever I wish with this belt?”_ Cinder asked the ghost, who nodded in acceptance.

Despite being completely humiliated and made fun of by her cohorts, a small smirk formed on her face.

 _“You’ve got a deal…”_ she began to say, just realizing she never caught the guy’s name.

“Just a passing through Kamen Rider…but you can call me Tsukasa. Remember that.” He tells Cinder, a smile forming on his face.

 _“Cinder Fall. And I think the two of us would be good friends, Tsukasa. But…what about my friends? Emerald? Mercury?”_ She asked Tsukasa.

“Unfortunately, they’re too close to Salem. For now, you’ll have to be on your own.” He tells them, as she proceeded to see a portal in front of her.

 _“Why do we have to abandon them? I’ve fought with them side by…”_ she began to say, before realizing what Tsukasa had meant.

Brining Emerald or Mercury with her now would lean Salem to suspicion of her belt. Something that currently, Cinder didn’t want. Well, that and run into Ruby again, but Salem was just as bad, if not worse for her. For once in her life, she actually had an unknown advantage over her cohorts. 

 

 And she wasn’t willing to waste that opportunity while she still had it.

 

The two walked into the portal that formed within the room, said portal disappearing into nothing.

From this day forward, a single question is asked…

_What does the Reborn Rider see in the World of RWBY?_


	2. A Kamen Rider Reborn! Decade Returns!

**Summary for the Chapter:**

> Cinder escapes from Salem, and faces her first ‘battle’ away from the Grimm Queen with Tsukasa by her side.

**Notes for the Chapter:**

> Ah, another chapter! Anyways, after some thought, I’ve now known where I want to take this story. Mostly. So, enjoy; gonna be pumping out more chapters soon! 
> 
> Disclaimer: I don’t own Kamen Rider nor RWBY. They belong to Toei and both Rooster Teeth and the late Monty Oum respectively.

”I’m a Kamen Rider!”- Talking. Simple as that. 

_“Wait...I’m a Kamen Rider?”_ -Those thoughts in Cinder’s head.

  __[ _Kamen Ride: Decade!]_ \- That good old DecaDriver 

 

 

_(Forest, Mistral)_

Sereneness laid the scene of the forest. Sure, the monsters known as Grimm roamed the forests across Remnant, but this one seemed a lot more quieter.

Maybe it was because of the recent missions of Huntsman and Huntresses had taken to take out the Grimm within the area.

Or maybe it’s because of a random portal that opened in the middle of the forest, bringing with it a former cohort to Salem and the ghost of a dead warrior from Earth. Both with similar pasts, and current presents.

“How does it feel being outside of Salem’s little circle and back into a public life?” Tsukasa has asked Cinder, as the portal closed once more behind them.

_“…Awkward. And absolutely vile.”_ Was Cinder’s one thought, staring toward Tsukasa, and then toward the driver. There was a question that she wanted to ask Tsukasa. She knew that he was probably sifting through her memories to build up his knowledge of what he called ‘this world’. Was he some ancient alien? A human who died at the wrong time?

_“Tsukasa…where did you come from? This belt-thing, our ‘bond’, you mentioning different worlds…where’d you come from?”_ Cinder asked in her mind, Tsukasa busy looking at a memory of Cinder ravaging Beacon Academy using her Fall Maiden powers. Alongside a really big dragon.

In Tsukasa’s mind, something familiar had clicked within her mind…and he realized what it was.

She was almost exactly like him once he regained his memories as Destroyer of Worlds.

Both used to be full-on villains. Both fought for what they thought was right. Both technically broke free from their old villain army/group.

And now, just like before, both were on the run. They needed to what was necessary to help preserve their future…no matter what they needed to do. They were tettering on the line between being good and being evil. They were…well, neutral. For now.

Shaking out of that realization, Tsukasa proceeded to answer Cinder’s question. “It’s a long weird story.”

_“I’ve seen a person with silver eyes actually take down both a giant dragon and myself, and had seen Grimm being born. I’ve seen a lot weirder and longer.”_ She tells him, the sound of Beowolves seemingly approaching.

“I’ll tell you after we deal with them.” He tells her, as Cinder released two fireballs in the direction of the Beowolves, two of them rapidly being vaporized by its effects. There were another five.

Cinder released three more fireballs, three more Beowolves burning from its effects. The other two were…less of a nuisance though. More of a full-on threat, being really big Alpha Beowolves. Behind them came something even bigger.

A really big Ursa.

“Well, certainly have your work cut out for you, Cinder.” Tsukasa tells her, the Ursa catching Cinder by surprise, as she was forced back through a few trees, until eventually stumbling into a big one, dropping onto the ground. Her Aura depletes a bit, but Cinder still felt as if the world had thrown the largest boulder it could at her.

Stumbling to get up, she formed something out of the flames of her Aura, the weapon being created almost out of literal thin air.

Her bow and arrow weapon. The same one that was forced to take the life of one Pyrrah Nikos.

With some hesitation in using her weapon, she aimed the weapon straight toward the Ursa, releasing the arrow, as it flew through the air, eventually smashing straight into the Ursa, turning him into nothing more than ashes and dust.

She still had the three Alpha Beowolves to worry about, as the three wolf-like Grimm charged toward Cinder, hungry for some Fall Maiden flesh.

Too bad they didn’t expect a surprise in the form of the Ridebooker firing out a card, slashing the three Beowolves through the neck, making the them evaporate, as Cinder ended grabbing said card. It showed a being’s face (mask?) with black lines across his mask. He had green eyes and a yellow gem-like object on his forehead. The words ‘Kamen Rider: Decade’ were plastered in white letters on the card.

_“What?”_ She asked in utter confusion, looking at Tsukasa…who simply smirked in response.

“I sense something…dark coming…GET DOWN!” Tsukasa Yelled, before Cinder jumped out of the way, a black sharp feather pinning the ground she stood on only a few seconds before.

_“A Nevermore…”_ Cinder grumbled, looking up toward the bird-like Grimm, as it sped its way back up. It was gonna fire another strafe of feathers straight in Cinder’s direction, if she didn’t do something.

“Use it…the belt, I mean.” Tsukasa tells Cinder, pointing to the DecaDriver in her hand, the Ridebooker also attached to said belt.

Hesitantly, Cinder attached the belt to her waist, the driver automatically strapping itself along her waist. She then looked to Tsukasa for more directions, as he points to the card in her driver, a slot being seen above to place the driver in.

She looks toward where the Nevermore was, as it flew straight up. She realized it was preparing for a second bombing run with its razor-sharp feathers on its wings. And then Tsukasa whispered a word into her ear.

“Hen…shin?” She asked in her barely audible voice, dropping the card into the belt.

_[Kamen Ride…]_

She pushed the now open sides of the front of the DecaDriver in, thinking that’s what she needed to do next.

_[…Decade!]_

Except the way she henshined…was different. The grey silhouettes of Decade’s armor still appeared, each silhouette marking the symbol of the 15 Shōwa Riders and 19 Heisei Riders. However, even Tsukasa wouldn’t expect the…new situation going on with the henshin.

Cinder was on fire, literally. Yet, strangely…she wasn’t yelling in absolute pain. She actually felt…comfortable with the flames around her.

The silhouettes eventually came together, as Decade’s colorless armor formed on Cinder. The flames from before spreading around her armor, as the armor started to be filled with color, all while a bunch of black cards shot out of the Ridebooker making their way to the front of her helmet. They eventually landed on the helmet, completing the transformation as a wave of fire spread in all directions, burning the forest.

The yellow gem on her helmet, slowly turned into a dark red; the magenta armor that was originally around the majority of Decade’s armor burned into more of a scarlet red. The armor itself seemed to turn into more a feminine shape. The normal green eyes on the Rider’s armor turned into a magenta color. Finally, the addition of what seemed akin to a small curtain spread out past her shoulder, making her seemingly almost wear half a poncho, the colors of it being gold and red, the Decade symbol on it in gold with what looked like a flame on the top.

Her transformation created a immediate wave of fire a few meters around her, as Cinder looked at herself.

“Welcome to the Kamen Rider Club, Cinder Fall. Not Gentaro’s club but…you know what I mean.” Tsukasa tells Cinder, slapping his forehead at both the mention of the original Kamen Rider Fourze, and the result from Cinder’s transformation; aka, a burning forest around her.

_“This…I…what…I don’t know what to say.”_ Cinder had thought in her head, staring at her new armor. The screeching of the Nevermore did bring her back to why she did all this in the first place.

“Looks like your flame powers combined with my driver…I honestly hate the change. Least no one would mistake for being pink.” Tsukasa mumbled under his breath, before sighing. “There should be a card in there. Shows a sword. Might want to use it.”

Cinder ended up quickly grabbing the Ridebooker, as the Nevermore was shooting up to the sky to begin it’s second bombing run. She found a card with a sword on it, slammingit into the driver, and doing the same thing as before.

_[Attack Ride: Slash!]_

The Ridebooker morphed itself into a sword in front of her, as the Nevermore began it’s decline down for a second run to fire its feathers.

She found one last card, this time one with the Decade symbol, as it quickly added the wisp from her armor to it. She added it into the driver.

_[Final Attack Ride: D-Decade!]_

_“Let’s see something…”_ Decade had told herself, opening her hand.

Soon, one of her glass swords had appeared in her hands, the other contains the Ridebooker in its sword form, as both of them became engulfed in flames.

Under her armor, Cinder gave the biggest grin that she had in a good while.

_“This is gonna be fun…”_ she thought, Tsukasa nodding as she jumped up into the air, raising both swords in the air as the Nevermore swooped down, passing through multiple cards that formed on the way to the Grimm. She eventually stuck both swords straight into the Grimm’s head, proceeding to run through it as the monster began diving straight for the ground. She would eventually jump from the Grimm once the two swords ran out of Grimm to slash, as she landed to the ground, the Grimm evaporating into nothing as the sound of the Nevermore crashing in the forest was heard.

After a brief moment of silence, Decade would stumble onto the ground, reverting to being Cinder once more, as she spat out a mixture of saliva and blood.

_“What...the…”_ she would keep thinking to herself, Tsukasa’s spirit leaning down toward the Maiden.

“Seems like using Decade’s power takes a significant amount of your…What was it…Aura, it was called?” Tsukasa had asked her.

“Considering everyone’s going to be onto you, my best suggestion is switching those clothes and going for more civilian clothes. Go incognito and all.” Tsukasa tells her, as Cinder slowly got up. “I’ve seen some smoke pillars rising from nearby. Must be some form of civilization…just hoping it isn’t Zawame City or something like that.

_“…Fine. Might as well get out of here before anyone else finds out. Grimm or Huntsman.”_ She says to Tsukasa in her mind, the Maiden beginning to walk her way toward a village, ignoring his thoughts about Gaim.

In the bushes a few meters away from them, one wild Narutaki stared at them almost creepily, smiling.

“So…Decade manages to get his new host on his side…that won’t last long, Decade.” Narutaki tells himself, before pulling out what seemed to be a Scroll.

“Excuse me; is this team CFVY of Beacon Academy?” He asked, a young woman answering the line.

“Yeah…whose this?” She asks Narutaki.

“A mysterious benefactor; the one called Cinder Fall? She’s here, in Mistral. I think she mentioned something about attacking Haven Academy soon; says she wants to finish off the Beacon kids while she can.” Narutaki responded, lying about most of it.

After a long silence (and most likely arguing among the group), a simply response came to him.

“We’re on our way.” She says, cutting off the comms.

 

 

 

 

 

 

 


	3. Mini-Chapter: A Time Before

**Summary for the Chapter:**

> Tsukasa thinks about a small memory of the past...

**Notes for the Chapter:**

> I do apologize for the long waits; school and all. Criticism is appreciated, and I hope you do be willing to wait on the remaining chapters; 5 and 6 are already being worked on as they speak!

The Wanderer.

Destroyer.

Savior and Husband.

The Man Who Destroys and Saved Worlds.

The Devil and the Angel.

A Hero.

A Kamen Rider.

Decade.

These were names for which Tsukasa Kadoya had once been called, when he still held the mantle of being Kamen Rider Decade. Back when he was alive, traveling across almost the incite number of worlds with best friends Kaito, Yuusuke…and his love, Natsumi.

As both him and his new host/ Decade, Cinder Fall, began making their way toward the nearby village that some traveling hobo named ‘Odero Village’, Tsukasa began thinking about various things.

Specifically about his past as a Kamen Rider, and as father to Narumi and Suki Kadoya.

________________________________

_(Flashback; December 21st, 2035; World of Decade)_

_A young twelve year old girl, who looked strangely similar to that of his wife walked up to an older Tsukasa Kadoya, whom had the addition of a full beard and sat in a bed in the Hikari Photo Studio, as he stared toward his child; Narumi._

_“Father…will I grow up to be one of those Kamen Riders like you?” She asked, Tsukasa placing a smile upon his face._

_“No…I don’t think you’d want to be a Rider, Narumi…dad would know best.” Tsukasa would tell Narumi, placing her down, as he took a sip of his coffee. “25 years of being a Rider will do that to you.” He tells them, as his loving wife, one Natsumi Kadoya, walked in, holding what seemed to be some tea. She looked rightfully a little mad._

_“Tsukasa; what’d I tell you about drinking coffee!” She Yelled, pulling a thumb up, freaking Tsukasa enough to hide in the covers of their bed, Narumi giggling at the entire ordeal. An eight year old also ran in, looking like a really young female Tsukasa, giggling as she held something in her hand, that thing clearly wanting to get off the child._

_“Natsumi-chan…I think Suki likes me a little TOO much!” Kiva-la yelled, as Natsumi redirected focus from hitting Tsukasa with the good old Hikari ‘Secret Technique’ to stopping Suki from trying to eat Kiva-la alive, opening the hand of the child and plucked the bat out._

_“Thanks Natsumi-chan; I didn’t exactly wanted to be eaten alive today. I swear, those kids in Kiva and Hibiki’s worlds were easier to handle than your own children.” Kiva-la told them, doing the equivalent of a wink._

_“Mommy! White chocolate!” Suki yelled, clearly thinking that the little bat was type of wrappable chocolate._

_“This is why we don’t take candy from Fangires, Narumi.” Tsukasa whispered toward Narumi who giggled, as Natsumi looked back toward Tsukasa._

_“Now…where were we Tsukasa-kun?” She asked, pulling out her thumb once more, as it was implanted straight into Tsukasa’s neck, as the former Destroyer began uncontrollably laughing, clearly affected by whatever Natsumi did, as Natsumi grabbed the cup, smiling._

_“Tsukasa Kadoya…you should know better than to sneak coffee from the great Natsumi Hikari!” Natsumi told Tsukasa, before the two would fall into a passionate kiss afterwards._

_“Tsukasa; Tsukasa!” Someone would shout repeatedly, Tsukasa world seemingly morphing out of the Hikari Studio…_

————————————————

(Present Day, Odero Village)

_“Tsukasa!”_ Cinder would tell in her mind to Tsukasa, who would snap out of the memory he was in.

“Oh…what the hell happened?” Tsukasa asked Cinder, until he turned, seeing that they were there.

“Oh; we’re here.” He tells her. “Right…so, we need to get you out of those clothes, and into something less conspicuous. Something that won’t exactly yell ‘Look at me, everyone; I’m the Fall Maiden, come and kill me!’.”

Cinder seemed annoyed by Tsukasa’s impression of the Fall Maiden, But she knew his directions were necessary so she would survive.

It was clear that was what she had to do to keep both her Maiden powers and Rider abilities together.

Especially with who was already beginning to get onto her.  



End file.
